Southwest Desert Flora

Scientific Name: Eryngium heterophyllum
Common Name: Wright's Eryngo
Also Called: Mexican Thistle
Family: Apiaceae [Umbelliferae] Parsley or Carrot Family
Synonyms: (Eryngium wrightii)
Status: Native
Duration: Perennial
Size: Up to 3 feet.
Growth Form: Forb/herb; erect, many branches on upper half of plant.
Leaves: Green turning silvery-green; leaves divided into sharp stiff lobes, rough and spiny.
Flower Color: Silver turning pale blue; flowers are small and clustered on a dome or egg-shaped head, surrounded by stiff bracts.
Flowering Season: August to October.
Elevation: 4,000 to 6,500 feet.

Habitat Preferences: Higher elevations in open wooded areas, plains, grasslands, sandy soils and along water courses.

Recorded Range: In the United States, Eryngium heterophyllum is found in southern AZ, far southwest NM, southwest TX and perhaps LA. It is also native in Mexico. However, the largest populations in the United States are found in southern Arizona.

North America & US County Distribution Map for Eryngium heterophyllum.

U.S. Weed Information: No data available.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: Eryngium heterophyllum is included on the USDA 2012 National Wetland Plant List as follows; Arid West, as FACW, Great Plains, as FAC, Western Mountains, Valleys, and Coast, as FACW
FACW = Facultative Wetland, Hydrophyte: Usually occur in wetlands, but may occur in non-wetlands
FAC = Facultative, Hydrophyte: Occur in wetlands and non-wetlands
Threatened/Endangered Information: No data available.

Comments: Wright’s Eryngo is an unusual looking, but attractive plant which has been used as feature placements in flower arrangements. The flowers remain true in color and form for long periods.

Although not a true thistle as in the Sunflower family, according to Arizona Flora, Wright’s Eryngo is known locally as Mexican Thistle.